Talcum powder, a beeswax mixture and petroleum jelly provide the best skin protection from long-term personal protective equipment (PPE) use, say scientists.
Researchers from Imperial College London have investigated which products create the longest-lasting protective layer between PPE and skin.
They custom-built a tribometer to assess friction and used it to test the friction between skin and polydimethylsiloxane (PDMS), which is a common component of PPE.
They tested commercially available products to measure how they changed the friction between PDMS and the inner forearm skin of a healthy 44-year-old male participant.
They found that while most products initially reduced friction by 20 per cent, some silicone-based and water-and-glycerin-based lubricants increased friction levels over time by up to 29 per cent compared with dry skin.
The best lubricants were those that were not absorbed into the skin, creating a long-lasting layer of protection between skin and PPE. Non-absorptive creams, like a coconut oil-cocoa butter beeswax mixture, and talcum powder were most likely to provide PPE wearers with long-lasting skin protection.
Two products reduced friction as time went on. Talcum powder reduced friction by 49 per cent on application and 59 per cent at four hours. A commercially available product comprising coconut oil, cocoa butter and beeswax reduced friction by 31 per cent on application and 53 per cent at four hours. A mixture of petrolatum and lanolin reduced friction by 30 per cent throughout testing.
When testing commercial moisturisers, the researchers found that friction on application was low, but increased drastically within 10 minutes of application. They say this is because the active ingredients attract water from the lower layers of skin to the upper ones, leaving it soft, unlubricated and breakable.
Lead author Dr Marc Masen, of Imperial’s Department of Mechanical Engineering, said: “We think of moisturisers as good for our skin, but commercial skin creams are often designed to absorb into the skin without leaving any residue. While this is fine for everyday moisturising, our study shows that a greasy residue is precisely what’s needed to protect skin from PPE friction.”